Relationship Between Expression of ras p21 Oncoprotein and Mutation Status of the K-ras Gene in Sporadic Colorectal Cancer Patients in Tunisia
| Autor: | Chaar Ines, Meriem Khiari, Bouraoui Saadia, Arfaoui Amira, Mzabi Sabeh, Souraya Sammoud, Amara Semeh, Kriaa Lilia, Lounis Amine, Khalfallah Taher |
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| Rok vydání: | 2012 |
| Předmět: |
Adult
Male Tunisia Histology Colorectal cancer Sequence analysis GTPase Oncogene Protein p21(ras) Biology medicine.disease_cause Proto-Oncogene Mas Gene Expression Regulation Enzymologic Pathology and Forensic Medicine medicine Humans Point Mutation Transversion Gene Aged Retrospective Studies Mutation Oncogene Point mutation Middle Aged medicine.disease Molecular biology Gene Expression Regulation Neoplastic Medical Laboratory Technology Cancer research Female Colorectal Neoplasms |
| Zdroj: | Applied Immunohistochemistry & Molecular Morphology. 20:146-152 |
| ISSN: | 1541-2016 |
| Popis: | INTRODUCTION The K-ras proto-oncogene encodes a protein (p21-ras) belonging to the family of GTP/GDP-binding proteins with GTPase activity. The activation of ras family genes plays an important role in colorectal tumorigenesis. Frequency of K-ras mutations and overexpression of the protein in colorectal cancer (CRC) vary between 14% and 50% and between 29% and 76%, respectively. AIMS We investigated the clinicopathologic characteristics of patients with CRC and their relationship with point mutations of K-ras oncogene codons 12/13 and ras p21 expression. MATERIALS AND METHODS K-ras codons 12 and 13 point mutations were examined by direct sequence analysis, whereas the ras p21 expression was evaluated using immunohistochemistry. RESULTS Statistical analysis of immunohistochemical results showed that the expression of ras p21 was correlated with the advanced age of patients (P=0.0001), whereas loss of signal was associated with mucinous histotype (P=0.0001). Mutations in the K-ras gene were detected in 12 of the patients with CRC. Mutations in K-ras gene were found in 12 of 52 tumors (23.07%), and 7 mutations were G→A transitions (58.33% of all mutations), 4 were G→T transversions (33.33%), and only 1 was G→C transversion (8.33%). A total of 83.33% of the mutation occurred at codon 12 and 16.67% at codon 13. Moreover, K-ras mutations were associated with the sex of patients (P=0.017). CONCLUSIONS Genetic K-ras alterations were rather low in the Tunisian population, but further study is necessary to unravel the molecular background of CRC. |
| Databáze: | OpenAIRE |
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